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April 10, 2012 -- The number of babies born to U.S. teens has reached a historic low.

New statistics from the CDC show the teen birth rate in 2010 dropped by 9% from 2009 to a new low of 34.3 births per 1,000 women aged 15-19.

That sets several records:

It's the lowest point since record-keeping began in 1946.

It's 44% lower than the most recent peak in 1991.

It's 64% lower than the all-time high set in 1957.

"If the 1991 rates had prevailed through the years 1992-2010, there would have been an estimated 3.4 million additional births to teenagers during that period," CDC researchers Brady Hamilton, PhD, and Stephanie Ventura write in their report.

Researchers say the public health impact of this decline is substantial because of the increased health risks faced by teen mothers and their infants. Public health costs associated with teen childbearing are estimated at $10.9 billion each year.

Teen Births Down, Disparities Remain

The drop in the teen birth rate from 2009-2010 included teens from all ages and ethnic groups. But there are still some gaps.

Teen birth rates dropped in all but three states: Montana, North Dakota, and West Virginia.

Overall, teen birth rates tended to be highest in the South and Southwest and lowest in the Northwest and upper Midwest.

Researchers say some of the variation in teen birth rates between states may reflect racial and ethnic differences.

For example, 2010 teen birth rates ranged from:

Asian or Pacific Islanders: 10.9 births per 1,000 teens

Whites: 23.5 per 1,000 teens

American Indian or Alaska native: 38.7 per 1,000 teens

African-Americans: 51.5 per 1,000 teens

Hispanic: 55.7 per 1,000 teens

SOURCES:Hamilton, B. "Birth Rates for U.S. Teenagers Reach Historic Low for All Age and Ethnic Groups," National Center for Health Statistics Data Brief, April 2012.News release, American Medical Association.